Temperature and flow velocity control for quartz crystal microbalances

Although quartz microbalances (QMBs) are widely used, controlling their temperature is a challenge. Here a slightly modified quartz microbalance, driven by an original SigmaDelta electronic interface, acts as temperature sensor, flow sensor, heater, and resonator; no interference between the oscillator circuit and the SigmaDelta interface has been observed. In comparison with traditional solutions, the proposed approach is more accurate, faster, cheaper, more flexible, and more power efficient. As an additional, unique advantage of our system, the flow velocity is automatically measured by the QMB sensor itself. The technological and circuit solutions reported here are general and may be useful in other applications where temperature and/or flow velocity must be controlled